In existing technical solutions, MEMS pressure sensors mainly include a capacitive type and a resistive type, wherein the capacitive type MEMS pressure sensor comprises a pressure-sensitive film, a substrate and contacts. The pressure-sensitive film and the substrate form a sealed vacuum cavity, and a capacitance plate formed by the pressure-sensitive film will make a reaction to external pressure changes. When external air pressures are changed, the pressure-sensitive film positioned above the vacuum cavity will be bent; therefore, a capacitance value formed by the pressure-sensitive film and the substrate will be changed, and further the change of this capacitance is read by an ASIC circuit to represent the external pressure changes.
The capacitive MEMS pressure sensors mentioned above detect the external pressure changes by single capacitor. Generally speaking, a capacitance change quantity caused by a change of the external air pressures is very small, and an error of detection carried out by adopting the single capacitor is very large. Besides, except for the external pressure changes, other interference signals will also cause the capacitance change. For example, stress, temperature and other common-mode signals all will affect a change value of the capacitance. These harmful signals will not be attenuated or filtered but will be output together with pressure signals. Thus, the precision and stability of pressure detection are further influenced.
Therefore, there is a demand in the art that a new solution to address at least one of the problems in the prior art.